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Biomedical subjects

N Yui

Publications and source records attributed to N Yui.

At least 109 records · Page 6Linked to original sources
PubMed1983

[Quantitative study of single photon radionuclide computed tomography--delineation of body contours].

Several methods to obtain the body contour which is necessary to reconstruct the quantitative images with single photon radionuclide computed tomography (SPRCT) are described in this paper. A multipurpose gamma camera system which is composed of 2 detectors, data processor and others were used to collect the data of SPRCT and body contour. An iterative reconstruction technique was implemented to reconstruct the image. Three methods for obtaining the body contour were tested. The first method utilizes X-ray CT data. The data which are obtained by GE CT/T are transferred to the data processor of SPRCT through the off-line magnetic tape and delineate the body contour. The second method uses a transmission source which was attached on the opposite side to detector. The third method uses gamma-rays which are generated by Compton scatter in the tissue of patient. The first and the second methods were able to use to obtain the body contour, but the contour obtained by third method was not accurate.

Gamma Rays↗
PubMed1982

[Clinical evaluation of transaxial bone imaging with 99mTc-phosphate compounds].

Single photon emission computed tomography using newly designed whole body imaging system which was composed of opposing dual gamma cameras, a rotating gantry and a sliding table was clinically evaluated for bone imaging. Two hundred and seventeen portions of various bone diseases were performed single photon emission computed tomography following conventional bone imaging with 99mTc-MDP (methylen diphosphonate) or -HMDP (hydroxymethylene diphosphonate) and the results were discussed. Transaxial images were sometimes superior than conventional images in the diagnosis of the tumor localization and extension of the facial bone. Combination of emission computed tomography to conventional methods also presented more exact informations for the diagnosis of the vertebral change. Separation of the overlapped radioactivities of the bone and the soft tissue is another advantage of the tomographic image, and cross-sectional images with enoughly high qualities were available in early time after administration of 99mTc-phosphate compounds. Useful diagnostic informations could be obtained by tomographic bone imaging combined with conventional imagings.

Adult↗
PubMed1982

[RCT image study by angular interval of sampling].

A multi-purpose gamma camera system which had 2 detectors of opposed position and was capable of radionuclide computed tomography (RCT) imaging was installed in Division of Nuclear Medicine, Chiba Cancer Center Hospital. In this study, the variance of RCT image due to the angular interval of sampling was analyzed. The full width at half maximum (FWHM) and full width at tenth maximum (FWTM) of point source were almost same for all sampling intervals investigated. The distortion of RCT images with uniform activity source could not be detected even for larger intervals. When the RCT images were obtained using a phantom contained 3 line sources and a bar phantom for RCT which were located at right angle with the plane of reconstruction, the images did not change between 1 degrees and 6 degrees of sampling interval, but for 9 degrees or more the distortion of images occurred explicity. For our system, sampling interval of 2 degrees was predicted from the theorectical calculation considering both resolution and statistical noise. But, results from the phantom studies of present work showed that sampling interval of 6 degrees was sufficient to reconstruct RCT images without distortion, and could be applicable to dynamic RCT images.

Models, Structural↗
PubMed1979

[Single photon radioisotope emission computed tomography image using gamma camera (author's transl)].

Single photon radioisotope computed tomography (RCT) images were obtained using the following devices such as conventional gamma camera, data processer for exclusive use of nuclear medicine (C.D.S.-4096), magnetic tape and medium size electronic computer FACOM 230-28S (48K) for multipurposes, which are routinely used for clinical purpose. To reconstruct the RCT image we made absorption correction by geometric mean of opposing counts considering the thickness of source and used the convolution integral method. The reconstructed images of phantom study resolved one centimeter clearly and were very similar to original. The RCT image of patient was acquired by the rotation of patients using the revolving chair and the handmade implement which settles the center of patient's head. Three dimensional informations were obtained by one examination with a gamma camera which collects two dimensional images. When using a gamma camera, therefore, not only a transaxial but an arbitraly RCT image will be important to contribute for diagnosis.

Brain Neoplasms↗